The present invention relates to an air-cooling/tempering device and an air-cooling/tempering method for a glass plate used for transporting machines such as automobiles, ships, railways, airplanes and so on or other various usage such as buildings and so on.
There has been known a method for bend-shaping a glass plate by transferring a glass plate heated to around a softening temperature in a heating furnace on a roller conveyor comprising a plurality of curved rollers (in, for example, U.S. Pat. No. 4,123,246). According to this method, the softened glass plate falls by its own weight, so that the glass plate is bent to meet the curvature of the rollers. In this case, the glass plate is bend-shaped in a direction perpendicular to a transferring direction of the glass plate.
In description, bend-shaping in a direction perpendicular to a transferring directions means that the shape of a bend-shaped glass plate is a shape curved around the axis of the transferring direction. In other words, the bend-shaped glass plate has a curved shape in cross section taken vertically along the axis of the transferring direction. xe2x80x9cBend-shaping along a transferring directionxe2x80x9d means similarly that the shape of a bend-shaped glass plate is a shape curved around the axis perpendicular to the transferring direction. In other words, the bend-shaped glass plate has a curved shape in cross section taken vertically along the axis perpendicular to the transferring direction. With respect to the shape of a curved plane formed by a plurality of rollers as described hereinbelow, xe2x80x9ccurved in (along) a transferring directionxe2x80x9d, xe2x80x9ccurved in a transferring directionxe2x80x9d or the like have the same meaning as xe2x80x9cbend-shaped in (along) a transferring directionxe2x80x9d. Also, in description of the curved plane concerning a direction perpendicular to a transferring direction, the same meaning as xe2x80x9cbend-shaped in a direction perpendicular to a transferring directionxe2x80x9d should be taken.
In this description, xe2x80x9cperpendicular to a certain directionxe2x80x9d means a direction perpendicular to a certain direction on a horizontal plane. Further, xe2x80x9cupperxe2x80x9d or xe2x80x9clowerxe2x80x9d in this description means xe2x80x9cupperxe2x80x9d or xe2x80x9clowerxe2x80x9d with respect to a horizontal plane.
In automobile industries in recent years, a demand of production of small quantity and large variety has been increasing, and glass plates having various curvatures are needed so as to correspond to models of automobiles. In a method described in U.S. Pat. No. 4,123,246 (hereinbelow, referred to simply as the ""246 method), it was necessary to exchange rollers to those having a curvature corresponding to a model of automobile. The exchanging took much time, and it was necessary to prepare rollers having a curvature required for the model.
Further, in the ""246 method, glass plates are transferred in a direction perpendicular to a direction to be bent. In this case, in bend-shaping a glass plate for a side window of an automobile for instance, the direction of a side of the glass plate when it is fitted to an automobile, corresponds to the direction of extending of the rollers. Accordingly, a stripe-like roller strain due to the contact of the rollers to the glass plate is formed in a vertical direction in a state of being assembled, and therefore, the stripe-like strain by the rollers is apt to be conspicuous. With respect to this, detailed description will be made hereinbelow.
When a glass plate is transferred by means of rollers, a so-called roller strain is formed by the contact of the glass plate with the rollers. Each of the rollers is extended in a direction perpendicular to the transferring direction, and they are arranged adjacently in the transferring direction. Therefore, the roller strain is formed in a stripe form in a direction perpendicular to the transferring direction of the glass plate.
Usually, it is difficult to find the roller strain by human eyes, and the roller strain is never an obstacle to visibility in use. However, it is seldom to find the roller strain depending on a condition of use and light incident to the glass plate. For example, a stripe-like strain extending in a vertical direction of a glass plate in a state that the glass plate is assembled to an automobile is easy to see in comparison with a stripe-like strain extending in a horizontal direction in an assembled state. Accordingly, it is preferred to make the transferring direction of the glass plate to be bend-shaped coincident with a horizontal direction in an assembled state.
On the other hand, when a glass plate is bend-shaped along the transferring direction, the thickness in apparent of the glass plate viewed from the frontage of an air-cooling/tempering device becomes large. Accordingly, in a conventional air-cooling/tempering device for a glass plate, a large frontage is required. When the frontage is made large, the distance between the air-blowing ports of the air-cooling/tempering device and the surface of the glass plate is large whereby the cooling performance is reduced.
As a bend-shaping method for a glass plate wherein the transferring direction of the glass plate to be bend-shaped is made coincident with the horizontal direction in an assembled state, and the frontage for introducing glass plates in the air-cooling/tempering device is made small, the method as described in U.S. Pat. No. 4,820,327 is known. According to this method, a glass plate is bend-shaped by heating the glass plate to around a softening temperature in a heating furnace and transferring the glass plate by means of a plurality of rollers arranged with an inclination in the transferring direction so as to curve the transferring path. In this method (hereinbelow, referred to as the ""327 method), since the softened glass falls by its own weight, the glass plate is bent to meet a curvature of the transferring path. In this case, the glass plate is bend-shaped in the transferring direction.
In the ""327 method, however, it was necessary to change the arrangement of rollers so as to form a transferring path having a curvature which meets a specified model among various models. The exchange took much time. Further, in the ""327 method, the transferring direction of the glass plate is changed to a vertical direction. Therefore, the entire equipment used for the ""327 method is inevitably large. Further, the transferring direction of the glass plate has to be changed from the vertical direction to the horizontal direction whereby a complicated mechanism is needed.
The glass plate bend-shaped as described above is, then, transferred to the air-cooling/tempering device in which air-cooling and tempering are effected. In this case also, the glass plate is air-cooled and tempered while it is transferred by a roller conveyor. Namely, the glass plate is transferred by the roller conveyor, wherein in such transferring process, the glass plate is air-cooled and tempered by blowing air to its upper and lower faces through air-blowing heads arranged upper and lower sides of the roller conveyor. In this case, the air-cooling/tempering device is preferably so adapted that the blowing of air is started when the entirety of the glass plate has completely been transferred between the upper and lower air-blowing heads so that the entire surface of the glass plate can uniformly be air-cooled and tempered. Namely, the air-cooling/tempering device is formed such that the blowing of air is started when the entirety of the glass plate is transferred between the upper and lower air-blowing heads, and the blowing of air is stopped when the glass plate is completely passed through the air-blowing heads. Then, the blowing of air is started again when the next glass plate to be air-cooled and tempered is, in its entirety, completely transferred between the upper and lower air-blowing heads.
However, the conventional method has a weak point such that in air-cooling and tempering the glass plate, another glass plate to be subsequently air-cooled and tempered can not be transferred between the upper and lower air-blowing heads until the glass plate subjected at present to air-cooling and tempering is completely passed between the upper and lower air-blowing heads, whereby, certain intervals of time is necessary for transferring. As a result, there was a drawback that glass plates can not effectively be air-cooled and tempered.
The present invention has been made in consideration of the above-mentioned, and the object of the present invention is to provide an air-cooling/tempering device for a glass plate, which can provide uniform cooling performance.
Further, it is an object to provide an air-cooling/tempering method for a glass plate, which can effectively air-cool and temper glass plates.
According to an aspect of the present invention, there is provided an air-cooling/tempering device for a glass plate which comprises a plurality of rollers for transferring a bend-shaped glass plate and for curving a transferring plane so as to correspond to a curved shape of the glass plate by being moved vertically; a plurality of upper air-blowing heads each disposed at an upper side between each adjacent rollers to blow air to an upper face of the glass plate transferred by the plurality of rollers; a plurality of lower air-blowing heads each disposed at a lower side between each adjacent rollers to blow air to a lower face of the glass plate transferred by the plurality of rollers; and an air-blowing head moving mechanism for moving vertically the upper air-blowing heads and the lower air-blowing heads depending on a vertical position of the plurality of rollers in a state that the distance between an upper air-blowing head and the lower air-blowing head opposing the upper air-blowing head is kept to be constant.
According to this, the upper air-blowing heads and the lower air-blowing heads are moved vertically in response to the vertical movement of the rollers, whereby uniform cooling performance can be provided.
Further, according to an aspect of the present invention, there is provided an air-cooling/tempering device for a glass plate which comprises a plurality of rollers disposed at predetermined intervals and supported by movable frames capable of moving vertically so as to move individually in a vertical direction to transfer a bend-shaped glass plate; upper air-blowing heads each disposed at an upper side between each adjacent rollers to blow air to an upper face of the glass plate; lower air-blowing heads each disposed at a lower side between each adjacent rollers to blow air to a lower face of the glass plate; a plurality of upper supporting frames attached with the upper air-blowing heads and supported to be capable of sliding in a vertical direction; a plurality of lower supporting frames attached with the lower air-blowing heads and supported to be capable of sliding in a vertical direction; pivot shafts each provided on each of the movable frames; disk-like pieces each provided on the same axis as the pivot shaft; swing arms each disposed between adjacent pivot shafts so that an end is supported rotatably by a pivot shaft at one side and the other end is supported by the pivot shaft at the other side; connecting arms each having an end connected to one of the lower supporting frames and the end connected to a central portion of one of the swing arms; and driven arms each having an end connected to one of the upper supporting frames and the other end mounted on an upper face of a central portion of one of the swing arms, wherein the plurality of rollers at a position where the glass plate is transferred are moved vertically with the transfer of the glass plate so that a curved plane is formed in the transferring plane formed by the plurality of rollers at that position, the curved plane being curved in a transferring direction so as to correspond to the shape of the glass plate bend-shaped; each of the rollers are sequentially moved vertically with the transfer of the glass plate and the curved plane is shifted in the transferring direction of the glass plate with the transfer of the glass plate; and the upper air-blowing heads and the lower air-blowing heads each disposed between each adjacent rollers are moved vertically so as to correspond to the vertical movement of the glass plate to transfer the bend-shaped glass plate and at the same time, to blow air to the upper and lower faces of the glass plate to thereby air-cooing and tempering the glass plate.
According to this, the upper air-blowing heads and the lower air-blowing heads are moved vertically in response to the vertical movement of the rollers. Namely, the vertical movement of the rollers causes the vertical movement of the pieces by the same quantity of movement as the rollers. When these pieces are moved vertically, there occurs a difference of height between adjacent pieces whereby the swing arms are inclined. The lower air-blowing heads are connected to the arms via the connecting arms with the result that the upper air-blowing heads are moved vertically in connection with the swing motion of the swing arms. In this case, since the connecting arms are placed at a central portion of the swing arms, the quantity of movement of the upper air-blowing heads is xc2xd as much as the difference of height between adjacent rollers. Further, the upper air-blowing heads are connected to the arms via the driven arms with the result that the upper air-blowing heads are moved vertically in connection with the swing motion of the swing arms. In this case, since the connecting arms are placed at a central portion of the swing arms, the amount of movement of the upper air-blowing heads is xc2xd as much as the difference of height between adjacent rollers. Accordingly, the upper air-blowing heads and the lower air-blowing heads are moved vertically in response to the vertical movement of the rollers, and their positions are kept to be an intermediate level between the adjacent rollers. With this, uniform cooling performance can be provided.
Further, according to an aspect of the present invention, there is provided an air-cooling/tempering method for a glass plate for air-cooling and tempering the glass plate by blowing air to an upper face and a lower face of the glass plate transferred sequentially by means of a transferring means through air-blowing heads disposed along the transferring means, which comprises using the air-blowing heads in which the air-blowing area is divided into a plurality of areas along a transferring direction of the transferring means; a step of stopping the blowing of air in the air-blowing area at an uppermost stream side in the transferring direction from the beginning of the transfer of a portion of the glass plate into the air-blowing area at the uppermost stream side in the transferring direction in the air-blowing head to the transfer of the entirety of the glass plate; a step of blowing air in the air-blowing area at the uppermost stream side in the transferring direction from the transfer of the entirety of the glass plate into the air-blowing area at the uppermost stream side in the transferring direction to the transfer of the glass plate to a downstream side of the air-blowing area at the uppermost stream side in the transferring direction; and a step of stopping the blowing of air in the air-blowing area at the uppermost stream side in the transferring direction after the entirety of the glass plate has been transferred from the air-blowing area at the uppermost stream side in the transferring direction.
Further, according to an aspect of the present invention, there is provided an air-cooling/tempering method for a glass plate for air-cooling and tempering the glass plate by blowing air to an upper face and a lower face of the glass plate transferred sequentially by means of a transferring means through air-blowing heads disposed along the transferring means, wherein the air-blowing head has an air-blowing area which is divided into a first area at an upper stream side in the transferring direction of the transferring means and a second area at a downstream side thereof, and wherein a step of blowing air in the first and second areas when the entirety of the glass plate is transferred into the first area, a step of stopping the blowing of air in the first area when the entirety of the glass plate is passed through the first area, and a step of reopening the blowing of air in the first area when the next glass plate is transferred into the first area to which the blowing of air has been stopped, are repeated sequentially.
According to this, when the entirety of the glass plate transferred by means of the transferring means is transferred into the first area, air is blown into the first area and the second area. When the entirety of the glass plate is passed through the first area, the blowing of air in the first area is stopped, and another glass plate to be subsequently air-cooled and tempered is transferred into the first area to which the blowing of air is stopped. Accordingly, time intervals for transferring glass plates can be shortened whereby the glass plates can effectively be air-cooled and tempered.
Further, according to an aspect of the present invention, there is provided an air-cooling/tempering method for a glass plate for air-cooling and tempering the glass plate by blowing air to an upper face and a lower face of the glass plate transferred sequentially by means of a transferring means through air-blowing heads disposed along the transferring means wherein the air-blowing head has an air-blowing area which is divided into a plurality of areas along the transferring direction of the transferring means, and wherein a step of blowing air from all divided areas when the entirety of the glass plate is transferred into the air-blowing area of the air-blowing head, a step of stopping the blowing of air in the order of areas through which the glass plate is passed, a step of reopening the blowing of air from the all divided areas when the entirety of the next glass plate is transferred into the areas to which the blowing of air is stopped, and a step of stopping the blowing of air in the order of areas through which the glass plate is passed, are repeated sequentially.
According to this, when the entirety of the glass plate transferred by the transferring means is transferred between the upper and lower air-blowing heads, air is blown from all the areas. Then, with the transfer of the glass plate, the blowing of air is sequentially stopped in the order of areas through which the glass plate is passed, and another glass plate to be subsequently air-cooled and tempered is transferred to the areas to which the blowing of air is stopped. Accordingly, time intervals for transferring glass plates can be shortened, and the glass plates can effectively be air-cooled and tempered.
Further, according to an aspect of the present invention, there is provided an air-cooling/tempering method for a glass plate for air-cooling and tempering the glass plate by blowing air to an upper face and a lower face of the glass plate transferred sequentially by means of a transferring means through air-blowing heads disposed along the transferring means, wherein the air-blowing area of the air-blowing heads is divided into a plurality of areas along the transferring direction of the transferring means, and air is blown from only the air-blowing area of the area which corresponds to the position of the glass plate during the transfer when the entirety of the glass plate is transferred into the air-blowing area of the air-blowing head.
According to this, when the entirety of the glass plate transferred by the transferring means is transferred into the air-blowing area of the air-blowing head, air is blown from only the air-blowing head of the area corresponding to the position of the glass plate during the transfer. With this, time intervals for transferring glass plates can be shortened, and the glass plates can effectively be air-cooled and tempered.